Guillermo Cifre González

About Me

I'm Guillermo “Willy” Cifre, a backend-focused developer experienced in building REST and GraphQL APIs, backend services with TypeScript and Python, and mobile/web integrations with React Native and Kotlin. My career is shifting toward Backend & Infrastructure Engineering, where I'm deepening my skills in Go, containerized environments, distributed systems, and scalable service design. I enjoy building reliable systems and continuously improving my understanding of software architecture and cloud fundamentals.

Technical Skills

Programming Languages

Golang, Typescript, SQL, NoSQL

Frameworks And Libraries

Express.js, React.js, Next.js, Node.js, GraphQL, Jest

Tools And Platforms

Git, GitHub, Docker, MySQL, MongoDB, Linux

Languages

Spanish, English B2

Work experience

Software Developer - [14/04/2025 – Today]

Wozzo

  • Build a RESTful API from scratch using JavaScript, MVC and Zod, API-Key authentication and full OpenAPI/Swagger documentation.
  • Build backend integration with OpenAI to generate personalized reports.
  • Develop a hybrid React Native app using Expo Router and WebView using TypeScript and Zod.
  • Implement GraphQL schemas, resolvers for queries and mutations, and MongoDB data models, integrating everything with optimized queries and mutations in the frontend.
  • Build mobile application features and functionalities in React Native using TypeScript.

Backend Developer - [01/02/2025 – 07/04/2025]

gasparaguilo.com

  • Design and write unit tests with Pytest to ensure code reliability.
  • Implement authentication and authorization using Flask-JWT.
  • Refactor backend logic to improve maintainability and performance.
  • Maintain and improved existing backend infrastructure.
  • Create queries to the database using SQLAlchemy.
  • Implement a version control system using Git Flow.

Fullstack Developer - [03/03/2024 – 01/10/2024]

Anysolution

  • Design and build application components in React/Next.js using TypeScript and Shadcn.
  • Build backend using Express js and TypeScript.
  • Make decisions about application software architecture.
  • Implement Docker to manage internal business services.
  • Use Docker to deploy applications.
  • Configure and manage Jira for software development.
  • Implement a version control system using Git Flow.

Android Developer - [20/03/2023 – 01/01/2024]

Barceló Hotels

  • Develop and implement new features using Kotlin, Jetpack Compose and MVVM architecture.
  • Maintain and refactor legacy XML-based screens to improve performance and code quality.
  • Contribute to the migration from XML to Jetpack Compose.
  • Design and implement scalable UI components and reusable patterns.
  • Define and adapt data models and use cases based on product requirements.
  • Debug, optimize and improve existing features to enhance user experience and app stability.
  • Use Git with Git Flow in a collaborative environment.

Frontend Developer - [01/05/2022 – 28/02/2023]

jordienric.com

  • Develop the landing page with Astro and Tailwind.